The present invention relates to the field of data tag devices, and more particularly to passive data tag devices which store time-sensitive data.
Data tag devices are in widespread use and are used to associate information with a particular item, or object. A data tag may be a passive device which can only respond to queries from tag readers, and which receives power to provide the response from the query signal itself. Alternatively a data tag may be an active device, having its own power source allowing it occasionally broadcast an unsolicited beacon signal.
Tags are used in a variety of industries including retail, transportation, medical/healthcare, and security, to name several. They are configured, accordingly, in a variety of form factors, as dictated by the particular application. Tags can be manufactured at such a low cost that they can be considered disposable in many applications. This is especially true of passive data tag devices. However, even though a tag's purpose may have been fulfilled, a conventional tag will persist indefinitely with its data in a retrievable format.
Tags are typically concealed in packing materials, containers, products, and even integrated into these items. When these items are disposed of, the information in the tags may be obtained by third parties. This is particularly true of active tag devices since their beacons signal may be received without any ready query or solicitation. It is anticipated that tag usage will increase.
Retailers can disable tags on items purchased at the point of sale. Disabling these tags adds an additional process at the point of sale, which is typically undesirable since it adds a cost in both equipment and time necessary to deactivate each tag. Furthermore, completely deactivating a tag at a point of sale may be undesirable for other reasons, such as warranty and return tracking, for example.
Another means for deactivating tags is for the consumer to use a so-called RFID zapper, which attempts to overload the circuits of the tag and destroy it as a result. A consumer may also simply destroy a tag to dispose of it. Of course, these methods assume the consumer both knows of the existence of the tag, and that the tag can reasonably be removed from the item with which it is associated. Active data tags, in contrast to passive data tags, contain their own power source, and can therefore maintain a clock in order to self-expire. Conventional passive data tags, however, receive their power from a query signal, and are therefore incapable of maintaining a clock.
Therefore there exists a need for a way to disable passive data tags to reduce the possibility that the tag information will be acquired by unintended parties.